Apparatus for parking automobiles



Sept' 25 1951 M. WALKER l 2,569,393

' APPARATUS PoR PARKING AUTOMOBILES Filed March 5, 1949 5 Sheets-Sheet 1 nventor Gttorneg Sept. 25, 1951 c. M. WALKER APPARATUS FOR PARKING AUTOMOBILES Filed March 5, 1949 5 Sheets-Sheet 2 INVEN TOR.- h C//nes M 0mm-Q ATTO EY .www

Sept. 25, 1951. c. M. WALKER APPARATUS FOR PARKING AUTOMOBILES Filed March 5, 1949 5 Sheets-Sheet 5 INVENToR.

5ePf- 25, 1951 c. M. WALKER 2,569,393

APPARATUS FOR PARKING AUTOMOBILES Filed MaI-Ch 5, 1949 5 Sheets-Sheet 4 g INVENTOR g BY '1114 SePt- 25, 1951 c. M. WALKER 2,569,393

APPARATUS FOR PARKING AUTOMOBILES Patented Sept. 25, 1951 Charles M. Walker, Manhattan Beach, Calif.

Application March 5, 1949, Serial No. '79,852

9 Claims.

vThe present invention relates broadly to apparatus for storing the maximum number of unit loads in a given ground area, and more specifically to an apparatus particularly adapted for use in parking a large number of automobiles in a limited ground area, such as in congested metropolitan shopping or'business districts where there is almost invariably insuliicient vacant land for adequateoff-street parking facilities. The land costs and demand for parking space are such as frequently require relatively high parking fees and frequentlyV a prohibition against al1-day parking.

While i1; is anticipated that the present invention will find its Widest application in connection with Vthe parking `of automobiles, it is also contemplated that the same principles might be utilized to excellent ladvantage in warehouses storing large unit loads such as packaged household furnishings, merchandise, and the like. In this case,1the articles stored in the Warehouse would be packedinto vans or loaded into mobile platforms, and would thereafter be carried by the apparatus of the .invention to the upper level floors of the warehouse for storage. The prin- .cipal advantage realized by the use of such an apparatus is the elimination of otherwise wasted space which must be reserved for corridors in conventional warehouses.

The primary object of the present invention, therefore, it .to provide means for, increasing the ,capacity :of a given storage space, and more particularly, to provided novel and efficient means for parking V`a considerably larger number of automobiles in a given groundareazthan'has heretofore been possible with any prior parking apparatus. v

Another obiect of the invention .is to provide an apparatus of the class described wherein the lvehicles ,areautomatically delivered to any desired storage location on the apparatus, or brought down from the apparatus to a loading or unloading station without requiring attention onthe part ofthe attendant except to manipulate theautomatic controls. This eliminates the necssity of having the attendant maneuver the cars around a crowded lot when putting a car into the spot to which it is destined-or when extricating the car therefrom when called for by the owner. Also, the present invention eliminates the need for having the attendant shift cars constantly from one place to another during periods Vof maximum `congestion in Vorder to open up lanes through which cars can be driven while being parked or withdrawn from .the lot. By thus CII 2 Y eliminating much of the .handling of. carsby .the attendants, the danger of damage to the .cars is greatly diminished.

As compared to the conventional vmulti-.level garage wherein the v,automobiles are driven up an inclined ramp to reach the upper levels, the present invention enjoys several distinct advantages, chief of which is themore eicient utilization .of the total available space 'by elimination or the Wasted ,space requiredfor the ramps and for the open driveways which must be left clear on .each oor level to permit the cars to be maneuvered around. The total oor area thus wasted in even a well-planned garage frequently exceeds the area actually occupied by cars, whereas in the present invention the .cars are parked more closely together and the space is utilized more completely, with the result that the area occupied by parked cars greatly exceeds the wasted area. Another disadvantage of the multi-level garage having an inclined ramp, is the fact that several skilled drivers are usually' required to drive the cars up the inclined ramps and to maneuver the cars around on the crowded floors, since many car owners lack the necessary confidence and driving skill. The wages of these drivers adds tothe operating costs'of the garage,

with a corresponding reduction in prots. lIn the present invention, the minimum of space is wasted, and the need for skilled drivers is eliminated; :hence the revenue for a given space increased `and theoperating costs are reduced. The foregoing objects are attained by the provision of `an apparatus consisting of a stationary loading structure having a lower level track and one or more upper level tracks, with Van up-elevator'at one end ofthe tracks and a down-elevator at the other end thereof. Traveling on the tracks are mobile platforms, each of which is adapted to receive an automobile or other load. In the case of a two-'level structure, both the upper and lower levels would be filled from end to end with these platforms, which are advanced in one direction along the lower level and in the other direction along the upper level. The up-elevator receives :the platform Afrom the lower level track and raises the same to the upper level track, where a pick-off mechanism removes the platform and pulls it onto the upper level track. To bring ya particular platform down to the loading or unloading station, the several mechanisms of the structure are set into operation, causing the platform to be advanced along the kupper level track onto the down-elevator at the other end thereof, where it is lowered to the ground level.

3 Another pick-off device then removes the platform from the down-elevator onto the lower level track. Suitable means is provided for operating the various units of the apparatus in the proper sequence so that the platforms are progressively advanced around the apparatus; traveling first along the lower level track, then up on one elevator, back along the upper level track, and down on the other elevator. The automobiles are loaded onto the platforms or unloaded therefrom at any suitable station along the line of travel on the lower level, preferably at the foot of either the up-elevator or down-elevator.

In the case of a multi-level structure having a plurality of vertically spaced upper level tracks, the apparatus is provided with only sufcient platforms to fill the upper level tracks, and when all of the platforms have been moved to their assigned levels, the lower level track and both of the elevators are empty. Each of the platforms is provided with means engageable only by the pick-off mechanism of the level to which the platform is assigned, so that only the platforms belonging on a particular track level will be removed from the up-elevator at that level, and platforms destined to other levels will remain on the elevator until they reach the level to which they belong.

Another object of the invention is to provide an automatic control system which will function to operate the mechanisms of the apparatus in a predetermined sequence and for a predetermined number of cycles to bring any desired platform on an upper level track down to the loading station.

A further object of the invention is to provide a safety device that functions to break the electrical circuit to the motor advancing the platforms along any one of the upper level tracks whenever it happens that the down-elevator at that particular level is already occupied by a platform descending from a higher level. This arrangement prevents the platform-advancing mechanism from trying to push a platform onto an already occupied portion of the down-elevator, which would, of course, cause damage to the apparatus and possibly to the automobiles carried thereon.

While the present disclosure illustrates and describes in particular detail a multi-level apparatus which is believed to be the preferred form of the invention, it should be understood that various other constructions will come within the scope of the invention in its broadest aspects. For example, it has already been mentioned that the invention might be embodied in a two-level structure, in which case both levels would be i'llled with platforms at all times, and the control mechanism suitably modified, as will be pointed out hereinafter. Also, in connection with the adaptation of the invention to a warehouse, as suggested earlier, it is contemplated that the frame structures of both the up and down elevators might be mounted on transversely extending tracks at opposite ends of the stationary structure, so that the elevators could be moved laterally into registration with any one of several rows of tracks on the stationary structure to serve the same, thereby eliminating duplication of elevators.

The foregoing and other objects and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiment thereof, reference being had to the accompanying drawings, wherein:

Figure l is a side elevational View of a multilevel apparatus embodying the principles of the invention;

Figure 2 is an enlarged side elevational view of the up-elevator at the left-hand end of the structure in Figure 1;

Figure 3 is a transverse vertical section through the up-elevator, taken along the line 3 3 in Figure 2;

Figure 4 is a horizontal section taken along the line 4 4 in Figure 2, and including also a top plan view of the first station along the track of the stationary structure;

Figure 5 is an enlarged sectional View taken at 5 5 in Figure 4, showing one end of the pickoff mechanism, and the manner in which it engages the pick-off hook on the platform;

Figure 6 is an enlarged sectional view of a detail, taken at 6 6 in Figure 5;

Figure 7 is a top plan view of the rst two stations on the top level track of the stationary supporting structure;

Figure 8 is an enlarged fragmentary sectional view taken alongside the conveyer chain mechanism at opposite ends thereof, showing the manner in which the conveyor chain drives the platforms;

Figure 9 is an enlarged transverse vertical section through the down-elevator at 9 9 in Figure l; and

Figure 10 is a schematic circuit diagram of the electrical control mechanism.

In the drawings, the apparatus of the present invention is seen to comprise a stationary structure designated in its entirety by the reference numeral 20 and consisting of a lower level track 2 I, and a plurality of vertically spaced upper level tracks 22, 23 and 24. The upper level tracks are arranged directly above and parallel to the lower level tracks, and located at the left and right hand ends, respectively, of the tracks is an upelevator 25 and a down-elevator 26. The stationary structure 2i) with its several track levels may take any desired structural form, and is herein shown as comprising a plurality of vertical posts 3i! which are spaced uniformly along the length of the structure on opposite sides thereof, and cross-connected by diagonal bracing members 3|. The bottom ends of the posts 30 are preferably embedded in concrete footings 32 in the bottom of a pit 33, so that the lower level track 2l is substantially level with the ground. The posts 30 on opposite sides ofthe structure are arranged in transversely aligned pairs, which are connected at each track level by a transverse channel beam 34.

RestingV on top of the transverse beams 34 and extending from one end of the structure 20 to the other end thereof are laterally spaced tracks 35 which may have any desired cross-sectional shape, but which are shown in the drawings as upwardly facing channel beams; The tracks 35 are adapted to receive the wheels 36 of mobile platforms '40 that are arranged end-to-end on the tracks, said platforms being adapted to receive and support the automobiles or other loads.

In the multi-level structure illustrated, each of the platforms 40 is normally assigned to one particular level of the upper level tracks, and to this end, means is provided for selectively removing the platforms from the up-elevator onto their respective track levels, as will be described in-more detail presently. ':Ihus,when1all .of the platforms 'have been loaded ,onto `the `upper ilevel ftracks, each of Vthe `upper level ttracks will be -filled 'from one end ito the yother with platforms which are :continuously returned r to :that :same level whenever the machine .is `set into ioperation. For .the-purpose .of @distinguishing the platforms of one level lfrom-those `of another, I have designated the platforms on the first of 'the upper levels `as 40a, while 4those on succeeding levels are designated 45h, Yand Mc. Means Lis also provided for advancing all of the Aplatforms on `any -one selected upper level track, so that -the platforms on that level are advanced 'toward and loaded onto the vdown-elevator. The plat- -forms can then :be successively loweredto Vthe ground llevel, wher-'e they are 'removed from the vdown-elevator onto lthe lower 'level track and 'then moved back to 'the up-elevator to Abe A:returned to .the Iupper vlevel track -to which they belong. In -this way, any :desired platform :can 'be brought Varound to the loading station to Areceive or discharge an automobile.

Each of vthe mobile platforms 74D comprises `a pair fof laterally spaced, longitudinally :extending channels A42 'which face :upwardly to provide tracks onto which the W-heelsof the vautomobile are driven. The vchannels 12 are connected :together at their front tand rear ends by transe verse members 43 Aand :41, and intermediate of their ends by cross-'bracing members '45. The

' wheels .'35 are mounted on the :endsrfof axles '4.3

' providing a cushioned contact between the lplatforms, whereby one platform can push another* if necessary. While the vdetails of thebumpers 53 and 51 arerof Vno consequence to thepres'ent invention, it will be noted that 'the contacting surfaces thereof `are 'smoothly rounded -'so fasto lprevent one 'bumper 'fromcatching onto another.v 50

Also mounted von and projecting forwardly from the frontlc'ross member S4i! of fea'ch of the platforms `is a pick-off hook 52` which .is adapted tofbe engaged bya cooperating .pick-.off mechanism 53 on the upper .level track 'to which the-:1'-`v uplatform lis assigned, Vwhereby the vplatforx'n Lis .removed vfrom `the I-fup-elevator 25 onto the tracks 35 of the stationaryrstructure. Thepickoff hooks 5.2 on the front ends :of the platforms 4D are all Aiden-tical in 'construction; andv :all-of 4the hooks on `the platforms of :any'g'iven' track level are located at the 'same ytranswerise, position on the cross member 'fl-3. However, the hooks '52 for each track level Vvare off-set laterally from those of the Iother levels, as l:best show-n in Fig# ure 3. Thus, for example, the hooks Y52 ofplatforms vlilla on the first upper level track `are 'illustratively located near the right hand side of the platform; while those of platforms Mib and 4t-c on the second and 'third upper level tracks are located `near the center -and left hand side, `respectively, of -the platforms. A l

Each of thepick-off hooks 52 Vis adapted to 'be engaged by'a pick-'olf mechanism 53 onj'the stationary structure `2`0 when the platform has been '6 raised by the "upeelevator to the level Ito which it belongs, and therefore each of 'the pickf'off mechanisms 53 is located in Vlateral alignment with 'the'pick-off hooksof the platforms for .that level. Thus, the pick-'off'mechanism 53 for the 'first upper level track 22 will only .engage the pick-.off hooks 52 of platforms killa, and will miss 'the pick-off hooks o'fp'latforms Alill? and Mic.

Mounted on the `rear cross member 44 of each :of the, platforms and projecting rearwardly therefrom is another pick-off hook 5d; this one being :engaged by a pick-olf mechanism 55 -on the lower level track -2| at the end adjacent the down-elevator 2.5. The purpose 'of the pick-off device 55 is `to pull the platform olf the downelevator 26 vonto the lower level track 2|, and since the platforms of all of the upper level tracks are returned valong the lower level track 2| to the up-elevator, the pick-off 'hooks 54 for all of the platforms on the apparatus are located at the same transverse location.

Also mounted on the lfront and rear cross members 43, 44 adjacent the left hand bumpers 50 and 5|, respectively, are forwardly and rearwardly projecting `brackets 55 and 51. Pivotally connected to the front bracket 53 by a pin is a downwardly hanging ratchet pawl 5I, the bottom end of which vis preferably formed with a v notch 62', as shown in Figure 8. The ratchet pawl -Bl is free to trail behind or to the left of the pin 6D as vthe platforms are pulled or pushed, as the case `may be, onto or along the stationary structure by the upper level pick-off mechanisms 53 the Afree end of the pawl ratcheting over the transverse `pins or rollers of a conveyer'chain 53 which extends longitudinally of vthe structure parallel to the tracks of each level. When ythe platform comes to astop, the notched end of the pawl 16| drops down into engagement with 'one of the lpins or rollers of the chain 53, and then when the chain begins to move, the pawl 6I is pushed along with it, thereby Amoving the platform along the track. t

Another ratchet pawl ,'64 Vis swingably connected by a pin G5 to the rear bracket 5l, and is likewise free to swing in the same fore and aft, vertical plane as thatin which the front ratchet pawl v(il moves. The rear ratchet pawl 64 is therefore engageable Aalso with the conveyor chain, 63, and the `latter is thus enabled to push against the rear endof the platform to move the same `onto the down-elevator. At this point, the chain passes down around the sprocket at the right hand end thereof, and the rear ratchet pawl 6'4 falls lfree of the chain down to the depending position shown at E -in Figure '8.

u', 1oelevator, will therefore be Yunderstood to apply also '-to the down-elevator; Each ofthe elevators comprises a supporting frame structure made up of fou-r verticalposts l@ located at the corners of the elevator, the bottom end v`of each of said posts being embedded in a concrete footing "Tl The two posts on each-side are connected together at their top ends by a fore and aft lextending beam l2, and are .also joined together along their lengths by crossed diagonal bracing members 13. VExtending between the two posts 1B at each side of the frame near the top and bottom ends thereof are drive shafts 'M and l5 which are jour-naled at their ends 'iin supporting bearings -16 mounted on the posts. Fixed to the top drive shaft 14 near the opposite yends thereof are sprockets 80, while other sprockets 8| are fixed to the opposite ends of the bottom drive shaft `|5. An endless chain 82 is trained around each pair of sprockets 80, 8|, and these chains travel in vertically extending channel members 83 and 84, which provide solid backing support for the chain. The channels 83 and 84 are attached to the cross bracing members 13 on the inside and outside edges thereof, respectively, and the chains 82 are driven in such direction that the portions traveling within the inner channel 83 are ascending, while the portions traveling in the outer channel 84 are descending.

The two bottom shafts 15 of the up-elevator are driven in synchronism by a motor'85 mounted on a platform 86 in the bottom of the pit 33. said motor being connected to the shaft by a speed-reduction and right-angle-drive gear box 90 having oppositely extending drive shafts 9| and 92, that are connected through speed-reduction gear boxes 93 to the ends of the shafts 15.

Fixed to the links of the chain 82 at equidistantly spaced intervals along the length thereof are bracket members 94 which support channel tracks 95. Each of the channel tracks 95 is attached to a horizontally aligned pair of brackets 94 on the two chains 32 at one side of the elevator, and the channel members are mounted on the brackets so that those tracks on the inside, ascending portions of the elevator chain face upwardly to receive the wheels 35 of the platform 40. The tracks on opposide sides of the up-elevator travel upwardly in horizontally aligned pairs, and the ascending tracks are also aligned transversely with the corresponding tracks 35 of the stationary structure. It will also be noted in Figure 3 that the brackets 913 are spaced along the chains 82 so that when the elevator comes to rest, each level of the elevator registers with the corresponding track level on the stationary structure 20.

The down-elevator is generally similar in all structural details to the up-elevator 25 except, of course that the channel tracks on the inside portions of the elevator chain descend instead of ascending. Also, the down-elevator is driven by a motor 96 which drives the chains 82 in the opposite direction to that of elevator '25.

The pick-off mechanism 53 of the upper level tracks and the lower level pick-off mechanism 55 are identical in construction and differ only in placement; the pick-olf mechanisms for the upper level tracks being located at the ends of their respective tracks adjacent the up-,elevator 25, while the lower level pick-off mechanisms 55 is located on the track 2| adjacent the downelevator 26. Since the structural details of the upper level pick-off mechanism 53 are more clearly illustrated in Figures 4, 5 and 6 than are those of the lower level pick-off mechanism 55, the description that follows will be directed particularly to the upper level pick-off mechanisms, although it will be understood that the same description applied equally well to the lower` level pick-off mechanism 55.

Each of the pick-olf mechanisms comprises an endless chain |00 which is trained around spookets |0| and |02. Sprocket |0| is rotatably supported by a bracket member |03 mounted on and projecting horizontally from the cross member 34 at the end of the track adjacent the upelevator 25. The other sprocket |02 is mounted on the drive shaft projecting from a speed-reduction gear box |04 which may be formed integrally with the housing of a motor |05, as

shown in Figure 4, although such integral construction is not essential. The motors |05 of the upper level tracks drive the chains |00 so that the upper courses thereof travel to the right, as seen in Figures 4 and 5, or away from the up-elevator 25. This upper course of the chain |00 is conned between the upwardly extending side anges of a channel member |06 and is supported by the bottom portionl thereof; said channel being mounted on the cross beams 34 and extending parallel to the tracks 35. The connecting cross pins of the chain |00 are preferably provided with rollers |01 which contact the bottom of the channel |06 to provide rolling support for the chain links.

Two of the links of the chain |00 at exactly opposite points thereon are provided with bracket members ||0 which project outwardly from the chain. In the preferred embodiment, the bracket member |0 comprises two laterally spaced plates which are joined together at their outer ends and apertured to receive a transverse pin ||2. The pin ||2 travels along the path A, shown in phantom lines in Figure 5, and engages the hook 52 of a platform 40 on the up-elevator destined for that particular level. The end portion of the hook 52 is cut out at ||3 to provide clearance for the bracket ||0 and for sprocket |0|. The phantom-line representation B (Figure 5) of the front end of the platform and pick-off hook 52 shows the manner in which the hook passes over the sprocket Y|0| While the platform is being raised by the up-elevator; the cutaway portion ||3 providing clearance for the sprocket so that the hook is enabled to pass the sprocket without interfering therewith. The solid-line representation of the front end of the platform and pick-off hook shows the position of these parts when the elevator comes to a stop with the tracks registered with the tracks 35 on the stationary structure.

While the platform is being raised by the elevator, the bracket member ||0 remains stationary at position C (Figure 5), and after the up-elevator has come to a stop, the pick-off chain |00 starts up in the direction of the arrowsy causing the pin ||2 to engage the downwardly bent end portions ||4 of the hook 52 as the bracket member ||0 approaches the top of the sprocket |0|. At this point, the pick-off chain |00, acting through the bracket member ||0, pulls the platform 40 off the up-elevator tracks 95 and onto the tracks 35 of the stationary structure 20. The length of the pick-off mechanism 53 is such that the platform 40 is pulled onto the upper level track to the position shown at F in Figure 4, at which point the pick-off mechanism comes to a stop.

The lower level pick-off mechanism 55, as explained earlier, is exactly like the upper level pick-off mechanism 53, except for the fact that the bracket members engage the rear hooks 54 on the platforms when the latter reach the bottom of the down-elevator 26; whereupon the platform is pulled off the down elevator 26, or toward the left as seen in Figure l.

In order to unload the platforms from any given track levelso as to bring a particular platform down to the loading station to receiveor discharge an automobile, means is provided for progressively advancing all of the platforms along the track in the direction from left to right, or towards the down-elevator. The aforesaid means is preferably in the form of the endless conveyer chain 63, which is trained around ontopfof and is suitably attached to the cross.

beams- 34 of.' the stationary structureV 26, and the topportion of the chain 63 is contained within and slides along the channel. The bottom channel |24 is supported from the undersides of the cross beams 34 by U-shaped brackets |25, and the bottom. portion of the chain rests on and slides along the channel on its returntrip'froml sprocket |2| to sprocket |20.

Sprocket |2| is attached to the output shaft of a speed-reduction, right-angleedrive gear box |26Y which isvk mounted on and opera-tively connected to ai motor |30. Thesuffixesa,l b, and e are added to the. reference numerals |30. in,- Fi'gures 1 and 10 to indicate that the motors con cerned, drive the conveyer chains of the rst, second, and third upper levels, respectively. Each of the conveyer motors |30 isv suitably mounted on a bracket |3| which is attached to the bottom flange of: the extreme right hand cross beam 34 of the stationary structureZl. rEhe motors |30 drive the sprockets |2| in a clockwise direction, which causes the platforms tov be moved along the tracks from left to right. As each 4platform is pushed onto the` downelevator, the rear ratchet detent E4 falls away fromthe' chain 63 to the downwardly hanging positions shown atposition Ein Figure 8.

The conveyer mechanism for the lower level track 2l isY designated generally by the reference numeral |35, and isv similar inconstruction to the conveyery mechanisms of the upper level tracks, except that its placement and direction of travel are reversed with respecty to the others. In. other words, the top portion of the bottom level conveyer chain travels from right to left, thereby advancing the platforms toward the up-elevator 25. The transverse placement of the' lower level conveyer mechanism |35 is in the saine'v'rtic'al plane as' the upper level conveyer mechanisms, and the chain is thereforeengaged by the same ratchetv pawls' |v and 64 on the platforms. Being freely swingable on their supporte ing'pivots, the ratchet pawls merely'trail behind' their pivots as the" platforms are pulled or pushed, as the case may be, onto or along the' stationary structure by the'lower level pick-off mechanisms 55, ratcheting over the conveyei chain until the platform comes to a stop.- Then, when the conveyer chain' is started up, the'pawl isV engaged and pushed alongwith it. The motor driving the bottom conveyermechanisms |351 is located at the extreme left hand end ofthe lower` which will lbe taken upV presently, it is believedv thatthe foregoing description is complete as toy all Yessential structural details, andthe discusbottom of the up-elevator 25. The automobilesare driven up a ramp or driveway |40 onto the channel tracks 42 of a platform waiting on the up-elevator, after which' the mechanism isthenf set into operation' to raisev the platformL toY its-' assigned level and then pull the loaded platformonto the tracks 3'5 of the stationary structure 20;.v

When theattendant-wishesto bring a particu-i lar platform of a given track level: down tothe loading station L, he operatesthe automatic con-- trol mechanism, thereby setting the machinery into operation to repeat. a predetermined sequence of operations until the desired platform` arrives at the loading station- The operational sequence referred to ccnsists'of the' following-f` four steps: (l) operation of the pick-off mechanis'ms 53 on all of thev upper level tracks,- and of the lower level pickeoff mechanisms 55,:` to remove any platfoms 'that maybe standing: on either elevator; (2)l the conveyer chain 63 of the selected track level is then driven to advance allv of theplatfor-'rr'isr on' that trackby a distance equal to one platform length, during which operation tl'ie platform at the extreme right hand end-of the track is pushed ontoV the down elevator 26'; (3) both elevators are then operatedtoA advance one level, i. e., upone level on the upelevator 25, and down one level on the downfio sion Which follows Will. turn now to the several elevator 2li.;` and (4^) the bottom conveyer chainV |35 is operated to advance r4all of they platforms on the lower level track 2| by vone platform length, during which operation, the platform at.

the extreme left handl end of the track is pushed onto the up-,elevator 275. This sequence of operations is repeated' the required number of times,

until the machine. comes to a stop vjust* after the desired platform has been ,pushed onto the loadingstation Lat the bottomy ofthe up-elevator 25.

At this point,` attention is directed to a safety device on'the down-elevator 26 whereby the conveyer chain mechanismsof the upper level tracks below the top level are prevented fromv being operated and pushing a platform onto the down elevator When the*A channel tracksof the downelevator at thatv particular level are already ec-l cupied by another platform descending from a higher trackV level. The device referredto consists of photo-electric cell mechanisms contained withinv housings |42 which are mounted on vthe diagonal cross braces 13 at. one side of the downelevator frame structure at each of the upper levels except for the top one.Y Directly across from each of the photoelectric cell housings |42 is alamp housing |44 having a projection lens |45l that directs a beam of light @across the. Both of the housings |42 and |44 are located atv such a level that the light beam G is blocked by the frameof the platform lill'when the latter is standing onV the down-elevator channel tracks rIhe photo electric cell mechanism in the housing |42 acts',

to open a relay in the circuit to the conveyer drive motor |30f of that particular track level when the light` beamGr isv blocked, and the conveyer chain is thus' prevented from pushingv another platform onto theY already occupied channel tracks of the down-elevator.

A typical control` circuit for operating the sev-v eral units: of the apparatus in the manner just described is shown schematically in the circuit diagram of Figure l0. illustrated is forV a multi-level structure having.

three upper levels,- with six platfform stationsv on each' level. This circuit can easily be kmodi-fled 1nan obvious manner Ato accommodate a difiere The particular circuit' 11 ent number of upper levels, or a diiferent number of platform stations per level.

Grouped together in a rectangular arrangement at the bottom of the circuit diagram is a plurality of push button control switches |56 which are arranged in horizontal rows corresponding in number to the upper level tracks, and each switch of each row corresponding to a given platform station on its associated track level. Each of the switches |50 is a normally open twopole, single-throw switch, which, when closed, transmits a momentary current impulse from a current source Xl to both a timer mechanism and to the coil of one of three relays |52, |53, and |54. These relays are in the nature of holding relays, and function to supply current continuously to the conveyer chain motors |30a, |301), and |300 of the upper level tracks until the operational cycle is completed.

Relay |52 is operatively connected to the conveyer chain motor |30a of track level 22 and is actuated by current impulses derived from any one of the control switches |50l in the bottom row. Relay |53 is operatively connected to conveyer chain motor |301) of track level 23, and is actuated by current impulses derived from any one of the control switches |50 of the center row. Relay |54 is operatively connected to the top conveyer motor |30c, and is actuated by cur-- rent impulses derived from any one ofthe control switches |50 of the top row. Current impulses from the bottom row of switches |56 are transmitted to the coil of relay |52 along a wire |55, which is connected to each of the right hand contacts |55 in the bottom row 0f switches. Current impulses from the middle row of switches are transmitted to the coil of relay |53 along wire |50; while another wire |6| transmits the current impulses from the top row of switches to the coil of relay |54. Wires |60 and |6| are likewise connected to the right hand contacts |56 on all of the switches |50 in the middle row and top row, respectively.

The two poles |62 and |63 of each of the switches |50 are connected by wires |64 to a current source X|, so that the closing of any one of the switches causes current to be carried simultaneously to both of the two contacts |56 and |66. It might be` noted at this point that whereever the reference letter X appears, it indicates connection to the current-carrying, or hot side of the line, 4-while the reference letter O denotes connection to the grounded side of the line. Thus a circuit may be completed from any one of the points designated X or X plus a suix to any one of the points designated O. The XV references may be connected to the same line terminal, in which case they would all be of the same voltage, or they may be connected to diierent current sources to suit the voltage requirement of the various relays, timers, switches and the like.

The left hand contacts |66 of each of the switches |50 are connected to the input terminals |61 of the electrical timer |5| by a plurality of wires |68, each of which is connected to those switches |50 requiring the same number of repetitions of the operating cycle to bring a platform from its position on the upper level tracks down to the loading station L. Thus, for example, if the switch at the eXtreme left hand end of the top row requires sixteen repetitions of the operating cycle to bring its corresponding platform down to the loading station L, the switches to the right of it will require fifteen, fourteen, thirteen,

CJi

twelve and eleven repetitions, respectively, while the switches of the middle row will require (reading from left to right) fifteen, fourteen, thirteen, twelve, eleven and ten repetitions, and the switches of the bottom row will require fourteen, thirteen, twelve, eleven, ten andrnine repetitions.

The mechanism of the timer |5| is operative to cause a current flow to be transmitted from a current source X2 to an output terminal |10 for a predetermined `measured length of time responsive to a momentary current impulse received from one of the switches through the input terminals |61. In the example given, a current impulse received at the extreme left hand input terminal |61 would cause a current flow from the output terminal |10 for exactly the period of time required to perform nine cycles of operation, while the input terminals to the right of it cause the current to flow for ten, eleven, twelve, thirteen, fourteen, fifteen, and sixteen cycles of operation, respectively. The extreme right hand input terminal is connected to a single-pole, single-throw switch |50', and gives a current flow for the duration of one cycle only. Switch |50' is therefore in the nature of a manual operation switch.

Referring back for a moment to the cross-connection of the left hand contacts |66 of the switches |50, we see that the extreme left hand switch in the top row of buttons is the only one requiring sixteen repetitions or cycles, and its contact |66 is therefore the only one connected to the sixteen-cycle input terminal of the timer. However, both the switch to the right of it and the one directly below it require fifteen cycles of operation, and therefore the contacts |66 of the two last-named switches are connected together so that if either one of them is pressed a current impulse is transmitted to the fifteen-cycle input terminal of the timer. In like manner the contacts |66 of the third switch from the left in the top row, second switch from thefleft in the middle row, and extreme left hand switch on the bottom row are connected together and to the fourteen-cycle input terminal of the timer; and so on down the line.

When one of the buttons |50 is pressed, two things occur simultaneously. First, a momentary current impulseris transmitted to the right hand contact |56 of the pressed switch, and this current impulse is transmitted to the coil of the relay (|52, |53 or |54) associated with that row of buttons. The circuit to the coil of the relay is completed through the ground connection O, thereby closing the normally open pole of the relay against its contact. At the same time, a current impulse is transmitted to the left hand contact |66 of the closed switch |56, and is carried to one of the input terminals |61 of the timer I5 I setting the latter into operation, which causes current to be transmitted immediately from current source X2 to the output terminal- |10. A portion of the current from' the output terminal |10 is transmitted along line |1| to another line |12 which is connected to the poles of all three of the relays |52, |53 and |54. Thus, as soon as the pole of any one of the relays is closed, current from the timer output terminal |10 is transmitted to the relay contact, where a portion of the current branches off to continue the energization of the coil so that the relay remains closed, while the balance of the current is transmitted to the conveyer motor associated with that relay. The Contact of relay |52 is con lines |13 and |14, respectively,- andthe coils ofi these relaysA are energized by the photoele'ctric cell mechanisms |42 whenever the light beam GV from the associated lamp housing |44 is interrupted. Thus, the presence of a platform 48 on the down-elevator at either the first or second of the upper levels causes the photo'electric cell mechanism |42 to open the relay and break the circuit to the conveyer motor for that level so that the conveyer chain will not beY operated, thereby pushing another platform onto the already occupied elevator. I-fVV the relays |16 and |11 are closed, current from any one of the lines |13, |14l and |15 will be transmitted through the motors |38a, |381), |38c` to line |88 which is connected tor the right hand contact of a sequence switch |8|. The left hand contact of the switch |8| is groundedv at O, and the pushpull pole of the switch. is normally retracted from the contacts thereof so that the circuit is open except when the pole is pressed upwardly;

Other sequencefswitches |812, |83 and |84- are arranged alongside ofswitch |8|, and these latter switches are likewise of thel normally open variety having two contacts which are-closed by al push-pull pole.

The poles ofthe sequence switches I8 |82, |83 and |84 are closed in the desired sequence and for the proper length of time by means ofr cams |85, |86, |81^and |88, respectively, which are mounted on a rotatable shaft |98. The shaft |98 is operatively connected to.` a constant speed,

`sequence con-trol motor |8| through a speedreduction gear box |92-, whereby the shaft |88 makes one complete revolution for each full cycle consisting of fourI operational sequences. Thus, forv example, if` We assume a five-second time interval for each ofthe four sequences (i. e., a pick-off mechanism, upper level conveyor elevators, and lower level conveyer), the shaft |98 would make one revolution in twenty seconds, closing each of the switches |82, |8|, |83 and |84, in the order named, for a five-second interval of time. Current for driving the motor |9| is taken from the line |1| by a connecting line |93, and the circuit is grounded from the motor to the ground connection O.

The left hand contacts of switches |82, |83, and |84 are connected by a line |34 to a current source X3, and the righty hand contact of switch |82 is connected by a line |95 to each of the pickoff motors |85 of the upper and lower levels. The circuits to the-pi'ck-ofi` motors |05 are completed to the ground connections O, and when the switch |82 is closed by cam |86, the motors are driven simultaneously to pull 01T any platformson the up or down elevators onto the levels to which the platforms are assigned.

The right hand contact of switch |83 is con-l nec-ted by a line |95 to the motor 85 of the upelevator and to the motor 98 of the downelevator, both of said motors being grounded to the ground connection O. Thus, when switch |83 is closed by cam |81, both of the elevators are operated for the required period of time to raise or lower the platform one level. The right hand contact of switch |84 is connected by a line 288 to the lowerlevel' conveye'r motor |30',

14, and the latter is operated when the switch is closed by cam |88.

rihus, eachtime that the shaft |98: makes one rotation, switch |828 is closed first, operating the-- pick-off motors |85; after which switch |8| is closed,- causing the operation of whichever motor of the upper level conveyers has a closed circuit due to the fact that its associated relay |52,

|53, or |54 has been energized.- Next, switch |83- is closed, causing the two elevators to advance one level;` and finally, switch |84 is closed, operating the bottom level conveyer motor |38 to advance the platforms on the lower' level by one platform length. Motor |-9I continues to operate until the current is shut or by the timer |5|', and therefore the number of revolutions made bythe shaft |198 depends upon the length oftime` during which current is delivered by theV timer |5|.

|81 receives the current impulse from the switches |58.

When the attendant wishes to clear the lowerl 1- |98 to make one complete revolution. Since no current is transmitted to the upper level' con veyer motors |38a, |3812', and |38c when: switch |58 is closed, it will be understood that nothing happens when sequence switch 8| is closed by its cam |85. rFhus, thev only propulsion of the platforms 85 along the upper level V tracks' is by the bumper-to-bumper push exerted by whichever platformis being pulledoi the up-elevator by one ofthe pick=ofr devices. Y

Another suggested method ofutilizing the apparatus is toload the platforms at the loading station L, and to unloady the platforms at an unloading station L (Figure 1) at the bottom of the down-elevator 26. In this case, the cars will be driven forwardly oir the channel tracks 4201" the platforms onto drivewayfor ramp 20|', and the empty platform wouldY then travel back along the lower level track 2|- to the loading station L to receive its next automobile. The advantage of* this arrangement is that it reducesv the amount of time necessary to bring an automobile down from one of the upper level tracks to the unload'- ingstation, which is decidedly advantageous during rush periods. A slight modification would obviously be required in the control mechanism, due to the fact that a, fewer number of operating cycles wouldy be required to bring a particular platform down to the unloading station L. Since the necessary changes are more or less obvious and will immediately become apparent to those skilled in the art, it is not deemed necessary to go into the same in moredetail at this point.

Still anotherv method' of operating the multilevel apparatus shown is to perform both the loading and unloading operations at station L'l As mentioned earlier, the time interval1 during which current ie delivered by the' timer depends upon which of the input terminalsr to the loading or unloading station L by the operation of the elevators. The switch |84, being unnecessary, would be eliminated, and line 20S carrying current to the bottom level conveyer motor |30 would be connected to switch |8| so that motor |30 would be operated simultaneously with any one of the upper level conveyer motors |30a, |30b or |300. The time required to bring a platform down from one of the upper' levels to station L can also be reduced further by having the conveyer motors operate simultaneously with the pick-off motors |05, in which case the cams |85 and |86 would be set to operate both of the switches |8| and |82 simultaneously. The cycle of operations would then consist of only two steps: (l) simultaneous operation of all of the pick-off motors |05, bottom level conveyer motor |30', and one of the upper level conveyer motors |3011, |3011, |3Ilc;v and (2) operation of both the up and down elevators to advance one level. Assuming five seconds for each sequence, the total time required to complete a cycle would be only ten seconds, and shaft I would then be speeded up to make one complete revolution in ten seconds. Cams |85 and |86 would close their respective switches simultaneously for one-half of a revolution of the shaft |90, and cam |81 would then close its switch |83 for the remaining one-half revolution. The timer |5| would also be modified, of course, to deliver current to the output terminal for periods of time graduated in ten second increments.

Where the apparatus is constructed with only two levels instead of with a plurality of upper levels, the operation need consist of only two steps: (l) operation of the pick-off mechanisms to pull the platforms off the two elevators and push the other cars on that level ahead of it; and (2) simultaneous operation of the two elevators to advance the same from one level to the other. In this case, the conveyer mechanisms would be omitted altogether and the only two sequence switches that would be needed are switches |82 and |83. The relays |52, |53, |54 would also be eliminated along with the conveyer motors; and single-pole, single-throw switches |50 could be used instead of the double-pole variety shown, since the right hand contacts A|55 of the double-pole switches would no longer be required. Also, shaft |90 would now be speeded up to make one revolution in ten seconds, and cams |86 and |31 would close their respective switches during one-half revolution each.

The foregoing examples are merely illustrative of the several ways in which the apparatus of the present invention can be constructed and operated. It is also contemplated that the automobiles might be loaded on the platforms il so that they travel sidewise down the length of the tracks instead of end-to-end as shown. This would have the advantage of reducing the number of elevators required for a given street frontage, since the width of each elevator would then be approximately equal to the length of the autcmobile instead of only the width thereof. Also, the percentage of unused area due to space reeuired for the downward travel of the elevator tracks on the outside portion of the chain 82 would be reduced. It should also be understood that the apparatus might take any other structural shape, such as reinforced concrete, brick, etc. It is furthermore Vcontemplated that the several levels might be closed off from one another by suitable partitions or re walls, and that various safety devices might be incorporated into the apparatus to prevent malfunctiorn'ng of any part of the mechanism.

While I have shown and described in considerable detail what I believe to be the preferred form of my invention, it is to be understood that such details are not restrictive, and that various changes may be made in the shape and arrangement of the several parts thereof without departing from the broad scope of the invention, as defined in the appended claims.

I claim:

l. Apparatus for storing automobiles and the like, comprising a lower level track and at least one upper level track, a plurality of mobile platforms arranged end-to-end on said tracks, said platforms being adapted to receive an automobile or other load, an up-elevator located at one end of said tracks and a down-elevator located at the other end thereof, said upelevator being adapted to receive said platforms from said lower level track and to raise the same to said upper level track, said down-elevator being adapted to receive said platforms from said upper level track and to lower the same to said lower level track, a pick-off device engageable with the platform on said up-elevator to pull the same onto said upper level track, another pickoff device engageable with the platforms on said down-elevator to pull the same onto said lower level track, an endless chain conveyer having one portion thereof extending parallel to said upper level track and traveling in the direction from said up-elevator toward said down-elevator, a ratchet pawl pivoted on said platformfor swinging movement in a fore and aft vertical plane, the depending end of said pawl being vfree to trail rearwardly and to ratchet over said conn veyer chain when said platform overruns said chain, and being engageable by said conveyer chain when the latter advances along said track, whereby the platform is carried along said upper level track by the chain, and another endless chain conveyer having one portion thereof exending parallel to said lower level track and traveling in the direction from said down-elevator toward said up-elevator, said ratchet pawls on said platforms being engageable by said one portion of said last named conveyer chain, whereby the platform is carried along said lower level track by the chain.

2. Apparatus for storing automobiles or the like, comprising a lower level track and a plurality of vertically spaced upper level tracks, said upper level tracks being arranged directly above and parallel to said lower level track, a plurality of mobile patforms adapted to receive automobiles or other loads, said platforms being adapted Vto travel along said tracks, and each platform being normally assigned to one particular level of said upper level tracks, an up` elevator located at one end of said tracks to receive platforms from said lower level track and to raise the same to said upper level tracks, a down-elevator at the other end of said tracks to receive platforms from said upper level tracks and to lower the same to said lower level track, a plurality of pick-01T devices for selectively removing platforms from said up-elevator onto the upper level tracks to which the platforms arev assigned, said pick-off devices being off-set laterally from one another at the different upper levels, means on the front edge of each of said platforms positioned laterally to be engageable only by the pick-off device at the upper levelV 1 track to which the platform belongs, another 17 pick-off device associated` with said lower; level track adjacent said down-elevator, and means on the back edge of eachrof said Vplatforms VpositionedV laterallyl to be, engaged by saidf lastnamed pick-olf device, whereby saidplatforms i are pulled off of the down-elevator onto said lower level track.

3. Apparatus for storing automobiles or ythe like, comprising a lower` level track and a plurality of vertically' spaced upper level tracks, said upper level tracks being arranged; directly above and parallel to said lower level track, a plurality of mobile platforms'adapted .toreceive automobiles or other loads, said platforms vbeing adapted to travel along said tracks,'and each platform being normallyassigned toroneparticular level of said upper level tracks, ,an upkelevator located at one end of said tracks tof-receive platforms from said lower level track and to raise the same to saidupper level tracksa down-elevator at the other end of said tracks, to receive platforms' from said upper level tracks and to lower the same to said lower levelztrack, a plurality of pick-olf devices for selectivelyremoving platforms from vsaid up-elevator onto the upper level tracks to which the platforms are assigned, each of said pick-off devices vcomprising an endless chain disposed between and running parallel to one of said upper level tracks, the endless chain of eachlevel being spaced transversely from the endless chains of the'other `platforms for pulling they same-,off theldownelevator onto said lower level track. l. o 4. Apparatus for storing 'automobiles or th like, comprising a lower levelV trackand a plurality of vertically spaced'upper level tracks,A

said upper level tracks beingA arranged directly above and parallel to said .lower level-track, a

- plurality of mobile patformsadapted-to, 'receive automobiles or other loads, said platforms being adapted to travel along said tracksfand each.

platform being normallyassigned to one particular level of said upper level tracks, an upelevator located at one end of said tracks to receive platforms from said lower level track and to raise the same to said upper level tracks, a down-elevator at the other end of said tracks to receive platforms from said upper level tracks and to lower the same tosaid lower level track',v a plurality of pick-off devices for selectivelyre'- `moving platforms from said'up-elevator onto they upper level tracks to which the platforms are assigned, each of said pick-off devices comprising an endless chain disposed between and running parallel to one of said upper level tracks, the endless chain of each level being spaced transversely from the endless chains of the other levels, bracket means projecting outwardly from each of said chains, a forwardly projecting pickoi hook on the front end of each of said platforms, said hooks being positioned transversely to be engageable only by the bracket means of the pick-off device on the upper level track to which the platform belongs, an endless `chain conveyer associated with each of said upper level tracks and extending parallel thereto, each of fsaidlchains havinga driving portion traveling in the direction toward said down-elevator, a

*ratchet pawl pivoted on and depending from each 'of said platforms, the bottom end of said pawl being free to ratchet over said conveyer chain when the platform over-runs the chain, and be- -ing engageable by said chain when the latter advances along said track, another pick-off device engageable with a hook on the rear end of Veach of said platforms for pulling the same off :the'down-elevator onto said lower level track,

and another endless chain conveyer associated withV said lower level track and engageable by said ratchet pawl to advance the platforms in the'direction toward said up-elevator.

I5. Apparatus for storing automobiles or the like, comprising a lower level track and a plurality of vertically spaced upper level tracks, said upper level tracks being arranged directly above and parallel to said lower level track, a plurality ofmobile platforms adapted to receive automobiles or other loads, said platforms being adapted to travel along said tracks, and each platform being normally assigned to one particular level of sadupper level tracks, an up-elevater located at one end of said tracks to receive platforms from said lower level track and to raise the same to said upper level tracks, a down-elevator at thepther end of said tracks to receive platforms from said 4upper level tracks and to lower the same to said lower level track, a plurality of pick-off devices i for selectively removing platforms from said upelevator onto the upper level tracks to which the platforms are assigned, each of said pick-off devices comprising an endless chain disposed between and running parallel to one of said upper Y level tracks, the endless chain of each level being spaced transversely from the endless chains of the other levels, bracket vmeans projecting outwardly from each of said chains, a forwardly pro- .jecting 'pick-olf hook on the front end of each of said platforms, said hooks being positioned y transversely to be engageable only by the bracket rmeansfofthe pick-oli' device on the lupper level trackto which the platform belongs, an endless chain conveyer associated with each of said upper .said {driving portion of said conveyer chain,

level tracks and extending parallel thereto, each of said chains having a driving portion traveling in the direction toward said down-elevator, a Amember on each of said platforms engageable by s with-a hook projecting rearwardly from the back end of each ofsaid platforms for pulling the same off the down-elevator onto said lower level track, another endless chain conveyer associated with vsaidlower-level track and operative to advance the platforms thereon in the direction toward said upf-elevator, and control means for automatically operating said pick-olf devices rst, then the conveyer chain of a selected upper level track, then both of said elevators, and finally said lower level conveyer chain, in the order named.

6. Apparatus for storing automobiles or the like, comprising a lower level track and a plurality of vertically spaced upper level tracks, said upper level tracks being arranged directly above and parallel to said lower level track, a plurality of mobile platforms adapted to receive automobiles or other loads, said platforms being adapted to travel along said tracks, and each platform being normally assigned to one particular level of said upper level tracks, an up-elevator located at one end of said tracks to receive platforms from yagrumes?,

I9 said lower level trackand tov raise'the'sametoisaid upper level tracks, a down-elevator at the other end of said tracks to receive platforms Ifrom'sa'id upper level tracks and to lower fthe samelto said lower level track, a plurality of pick-off devices vfor selectively removing platforms from said :up-

elevator onto the upper level tracks `to :whichi'the platforms are assigned, conveyer means :associated with each of said upper `level tracks .and engageable with the platforms thereon-tol'advance` the same toward said down-elevator, another pick-off device engageable with the platforms at the bottom of said down-elevator to pullthesame onto `said lower level track, other conveyer means associated with said lower level track andengagefab'ler with 'the platforms vthereon Ito zadvance ."tlie same toward `said 11p-elevator, 4and sa lcontrol circuit 'Shaving a plurality of vswitches provided thereonioperable to .actua'tesaid .pick-'off devices, conveyermeans, and elevators in arpredetermined 'sequence and for a predetermined number of cycles when oneof said switches is closed, 4where- 1by`aplatform in `a specic position =on :one-of sa'id'` upper level trackstmay 'be brought down automatioally'to aloading or unloading'stationf'on 'said `lower level track.

7. Apparatus for storing vautomobiles or the f-like, comprisinga lower vlevel"trac`k1and Ya ,plu-

'rality of vertically spaced rlupperzleveltracks, 'said upper level tracks'b'eing arranged :directly :above van'd'parallel to said lower level track, aplurality of 'mobile platforms vadapted to lreceive .autovmobiles or other loads, said platforms rbeing adapted to ltravel 'along -said tracks, 'and .reach 4platform 'being normally assigned "to one `particular :level of said K:upper level tracks, an -upelevator ilo'cated atson'eiend of said tracks to/f'receive platforms'from said lower level .trackjand to kraisevthe same vto said upper level ,ltracks, A=a

vdown-elevator 'at lthe other end 4of said 'tracks toy .receive platformslfrom said upper vleveltracks'1and to .lower the'isame lto said klower .level tracks, la plurality io'f 'pick-off devices forselectively-fre moving 'platforms from said` rip-elevatoriontolathe upper level^tracks to whichthe'platf'ormsf are'a-sto pulllthefsame -onto said lower level.'traclgzother conveyor means associated with 'said'lower .level 'trackand engageable withthetplatforms thereon to advance the same toward said up-elevatonand a safety .deviceresponsive to 'the .presencefof .one f-said platforms on said down-elevator at'one of said upper levels for interrupting thefrcircuitto Vthe 'motor of said fconveyor-means forthatllevl,

so fas lto prevent the operationthereoffas 'long-as fao Lthereis-a platform on the-down-elevator at `that level.

'fsofas to "prevent ,the operation thereof as long as said beam of light is interrupted by `a platform on .the down-elevator` at that level.

QfAppar-atus for storing automobileslor the like, comprising a lower level track-and a plu- Aralityfof vertically spaced upper leVeLtracks, said upperlevel tracks being `.arranged directly above and parallel ltosaid lower level track, a plurality of `mobile platforms adapted to receive automobiles or .other loads, .said .platforms rbeing adapted to'travel along said tracks, and each platform being normally assigned to .one particular 'levelof said upper level tracks, an up-elevatorlocated at one end of said tracks to receive platforms from'said lower level track and to raise the same to said upper level tracks, a down-elevatornattheother `end ofsaid' tracks to receive platforms 'from saidv upper I'-track levels and to lowerlthensame to said lower track level, a plurality Aof pick-off devices for selectively removing platforms-from saidup-elevator `onto .the upper :levelitracksto which thepaltforms are assigned,

Vconveyer ymeans eassociatedwith each of said upper'level tracks and engageable with the platformsthereon to advance the same toward said down-elevator, anotherpick-olf ldevice engageable'with the platforms atthe bottom-end of said vdown-elevator to pull thesame -onto said lower `level track, other conveyer? means yassociatedfwith said lower level track and engageable Vwiththe platforms thereon .to advancethe same toward'said 11p-elevator, and a selective, vautornaticcontrol circuit embodying :motor-'drivnfmeans 'for actu- I ating said `pick-off devices, itl-ie lconveyer means lof Yione :selected upper level.` track, :saidwelevators 4landfsaidlower level :conveyerrmeans` inv a predetermined sequence and for :ai predetermined num- .ber vof cycles, whereby-anylplatform on said upper ylevel tracks can 'be brought down automatically stofa loading or unloading station onvv said lower level xtrack. Y Y Y CHARLES WALKER..

REFERENCES CITED The following references are of recordrin the 

